Pyranthrone composition comprising an inorganic halogenate and process for dyeing



Patented Apr. 10, 1951 PYRANTHRONE COMPOSITIONTCDMPRISINGT AN INORGANICHALOGENATEAND PROG-v ESS FOR DYEING Jerry M.'. Mecco, Somerville,1. NJ.-., assignor to American. Cyanamid Company, New York,,. N: -Y.,acorporationof Maine.

No'Drawing: Application November'30, -1949 Serial No. 130,360?

and} it, and. itsedib'romo. derivative. (o: 1.. 1098),

are. well. known vat dyesof golden-orange color. When these dyes aredyedfby ordinary vat dyeing processes,.,whieh involve astrongalkaligsuch. as' sodium hydroxide and a reducing agent, such assodium hydrosulfite, there is a loss'iii strength and brilliance,whenathe' dyeing operation is carriedout. at. high. temperatures. Onthe. other hand,. high temperature dyeing presents... such large,practicall economic advantages, that. the properties of thesetwo. dyes,for dyeing. at high temperatures, approaching that" of boiling, water,has .hampered their economic exploitation.

High temperature dyeing. usually. improves dye penetrationand/or;level'ness,. particularly with such fabrics as nylon; The fast-dyeingwhich is possible. at high temperatures also makes various continuousandi semi' continuous processes. possible.

In referring to a "dye bath"it' shouldbe under stood that we areconsidering'the situation at" the time the dye is aflixedtmthe fabric.In many processesthedyestuif is present ina dye bath .or vat .insolutioni'n the form ofithe reduced leuco comp,ound',andfthe goods areintroduced into this bath. In other processes, such as,,for example,

pigment dyeingjprocesses; which lend themselves to continuous andsemi-continuous processesof the package: dyeing; variety, the. dyestufimay "be originallyincorporated loosely in the'fiber in the;

form of a" pigmentand'then" reduced" by; the dye 50' in. the-fiberThroughout. -thisr2case; the term 55 12;-Claims. (Cl; 8-34).

2. dyebath? willtbe used-to cover both types. of situation.

We. have found 'that the addition of an inorganichalogenate, suchas.chlorates, bromates,.and iodates, removes v:the disadvantage notedinordinary high-temperaturadyeing with pyranthrone,v and its.halogenated derivatives. A all. off the alkali metal halogenatesbehavein thesamemanner, sodiumchlorate is,-,. ordinarily,. used becausevofitslowcost- The particular metal cation, however, does not .appeartoenterinto the. mechanism,, by which the halogenates:achievetheiriinproved'i. results. Therefore, practically, sodium halogen.- ate. ispreferred. a

It .islnotknownhow thehalogenate operatesl'in. preventing. loss .ofstrength vand brilliance in. high temperature. dyeing. with.pyranthrone; and; ac.- cordingly, the present invention. is. notintended to. be limited. to. any, theory. of. action. In particular, thephenomena. which. underlies the.pres.-- ent inventionareall'the-moremysterioushecause,. as. is. described: and claimed. inmy. copending, application .SerialTNo. 1301357,filed'November 30', 1949;inorganic halogenates. exert a: similar action" with vatj dyestuffs,which are sensitive to. over reduction or decomposition athightemperatures. In. the. caseiofthese. dyes; which are easily, decomposedor over reduced; it is. possible that the halogenate may, a'ctas somefkindv of'a reduction buffer. In'the caseiofpyra'nthrone and 'its'ha1o'--genated. derivatives; however, such an explanation .isnot'tenablabecause it is a known characteristic of these dyes .thattheydo not show any appearance of decompositionorover'reductionin" bathsupto the. boiling.point ofwa'ter. In'spite of this. well known stability;of" the dye'stufisythe,v halogenates exert their beneficial" action to amarked degree. It is obvious" that'fact'orsotheT than prevention ofoven-reduction or decomposition at high. temperatures. must. be.involved.

Whatthese. other factors. are, however, hasistill. not. been.determined" The advantages. of. therpresentv inventionare. obtainedbothwithpyranthrone andits halogenated derivatives. The. degree ofimprovement,. however, is considerably. greater." withdibromopyranthrone than with .pyranthrone. itself..

It is .an advantage. of. the present invention that. the amountof..inorganichalogenate.to.:be.. used.is,. not? critical. 'Ihere;is-,-.of, course a lower limit; and. it. has been. found that when.thes amount 01:. halogenate; is.- less-than oneequa-rter by weight: of.-the: content". of -actual.-- dyestuft in r the bath-, the; improvementsare notesuificientlm marked i to be of; practical. value. Abova-this-sminimum; results.-

improve for a while, with increasing amounts of halogenate, but soonreach the point at which greater amounts of halogenate do not give anyimprovement. This point is approximately 16 parts by weightqthalogenateto 1 part of dye. However for practical operation, the improvementobtained with much smaller amounts (for example, from 1 to 3 parts ofhalogenate per part of dye), so closely approach the maximum improvementobtainable, thatllarger amounts of halogenate do not produce sufiicientimprovement to justify the additional cost. Even the upper limit of 16parts of halogenate does not'represent the maximum amount whichcan-be-used, without destroying the improvement in strength and bril- 4in warm water to remove the excess acid, soaped at the boil for tenminutes in 0.1 soap and 0.1% soda ash solution, rinsed and dried. Thecolor was a bright orange and the yarn was dyed a full shade. I 1

A second dyeing was made liketh'e above except the 1.5 parts of sodiumchlorate were omitted from the dye bath. The material dyed in thisliance, which is the purpose of..the present .in-

vention. Even when 50 parts of halogenate. to 1 of dye are used, theimprovements are still to be noted; but, of course, such enormousamounts of halogenate are only of theoretical interest.

Another advantage of the present invention is that the manipulativetechniques of high temperature dyeing are not, in any way changed byits'use. Dyeing conditions remain the same as do dyeing times; and theonly change is that the shades obtained are stronger and brighter.

I The optimum amount of inorganic halogenate who used depends, to someextent, on the temperature of the dye bath and on the time during whichdyeing takes place. In general, the faster the dyeing, the smaller theamount of halogenate whichcan caused to give results so closelyapproximating the optimum results, as to make larger amounts ofhalogenate practically unnecessary. When dyeing time is longer, as iscustomary; additional amounts of hydrosulfite are added to makeup forhydrosulfite oxidized by mean, or by other factors.

It is an advantage of the present invention that it'may be applied inseveral ways. ample, vat dye baths can be made up by adding all of theingredients, that is, dye, alkali, reducing agent and halogenate, toproduce a finished bath. Another method which has the practicaladvantage of makingit unnecessary for the dyer to control closely the"proportion of all ingredients going into the dye bath, is to blend withthe dyest'u'fi a suitable amountof'halogenate to form'a p'owder'or apaste. This blend, which constitutes a new article of manufactureincluded within the scope of the present invention, may be sold; Thedyer may then prepare his bath with the dyestuff blend, the alkali andthelr'educing agent in any convenient order.

The invention, will be illustrated in greater detailin conjunction withthe following specific examples. Parts are by weight.

Example 1 10 parts of cotton yarn were dyed in a bath containing about0.09 part of the real dye having Qolor Index 1098, three parts of sodiumhydros'uliite, 1.5 parts of sodium chlorate in 400 parts o'f water. -Thebath'was heated for five minutes at about 200' F.-during which time thevat dye was reduced, after which thecotton yarn was entered and dyed for60 minutes at about 200 F. The dyed yarn was then removed, and theexcess dye liquor extracted from the yarn. The remaining dye on the yarnwas then oxidized for five minutes in the air at room temperature, afterwhich it was immersed in an oxidizing solution consisting oi 0.1% sodiumperoxide (100 volumes) and 0.1% glacial acetic acid'solution for tenminutes at 140 F; The dyed yarn was then rinsed For ex- .repeatedexceptthe dye having Color Index No.

1096- and 1.5 parts of sodium hydrosulfite were added after 5minutes andanother 1.5 parts were added after minutes. The color value of the yarndyed'ii'ithis'bath is a stronger and brighter orange than that of theyarn dyed in the control sample in which no sodium chlorate is present.

Example 3 'Ten parts of cotton yarn were dyed in a bath containing 0.09part of the real dye having Color Index No. 1096, 3 parts of sodiumhydroxide, 3

parts of sodium hydrosulfite, 1.5 parts of potas- Example 4 Theprocedure of the preceding example was repeated except the dye havingColor Index No. 1098 and 1.5 parts of sodium hydrosulfite were .addedafter 5 minutes and another 1.5 parts were added after. 20 minutes. Thecolor value of the yarn dyed in this dyebath is much'stronger andbrighter orange than that of the yarn dyed in the control sample inwhich no potassium bromate is present.

Example 5 Ten parts of cotton material-were dyed in a bath containing0.09 part of the real dye having Color Index No. 1096, 3 parts of sodiumhydroxide, 3 parts of sodium hydrosulfite, 1.5 parts of potassium iodatein 400 parts of water. The bath was reduced for 5 minutes at 200 F.after which the cotton was entered and dyed for 60 minutes at 200 F. Thedyeing was bright orange and the cotton was dyed a full shade.

A second dyeing was made exactly as above except the 1.5 parts ofpotassium iodate were omit-' ted from the dyebath. The cotton materialdyed in this bath was a weaker shade of orange.

Example 6 Three parts of the dye having Color Index 1098 and containingabout 18.5 %"real dye were mixed with 3 parts of sodium chloratek Thismixture was then added to 1170 parts of water'at 160 F. To this wasadded 35"parts of' 30 Bet sodium hydroxide, after which the temperaturewas. again adjusted to 160 F. and 9' parts of sodium hydrosulfite addedand dissolved. The temperature was maintained at 160 F. for 15- minutes,after which time the color was reduced. This will be referred to asthestandard leuco solution. 400 parts of this reduced dye solution werethen transferred to a separate dye beaker.

Twenty parts of natural cotton yarn were prewet with approximatelysolution of pine oil soap,'the excess removed by squeezing, and the yarnthen entered into the 400 parts of reduced vat dye and dyed at 160 F;for 15 minutesi -The dyed yarn was then removed and the excess dyeliquor extracted. The remainingdye onthe yarn was, then oxidized forfive minutes inthe air at room temperature, after which it was immersedin an oxidizing solution consisting of 0:1 sodium peroxide(100vo1umes)'- and 0:1% glacial acetic acid solution for minutes at'140"F; The dyed yarn was then rinsed in warm water to remove the excessglacial acetic acid, soa'ped at the boil for ten minutes in 0.1% soapand 0.1% soda ash solution, rinsed and dried.

A, control dye bath was prepared exactly like the above except thesodium chlorate was omitted. This was used to make a control dyeingusing the same procedure as above. Theyarn dyed in the bath containingthe sodium chlorate was stronger, redder and brighter than the con troldyeing.

Example 8 The procedure of Example '7 was. repeated. ex.- cept thedyeing was made, for 1 hour 45 minutes after which the differencebetween the dyeing made in the bath containing the sodium chlorate andthe control dyeing was even greater than that indicated in the precedingexample.

Example 9 The procedure of Example 1 was repeated except rayon was usedin place of the cotton and the resultswere similar to those obtained inExample 1.

ExampleIO;

The= procedure-0t the preceding example was repeated exceptlinen wasused inplace of the rayon and the results were similar to those obtainedin the precedin example.

Example 11 The procedure of the preceding example was repeated exceptnylon was used and the temperature was raised to the boil. The dyeingmade in the bath containing the sodium chlorate was strong and brightwhereas the dyeing made in the control bath was dull and yellow.

Example 12 The procedure of Example 1 was repeated except 0.025 partsodium chlorate was used instead of the 1.5 parts used in Example 1. Theresults showed an improvement in the appearance of the dyeing made inthe bath containing the sodium chlorate over that made in the controlbath but this difierence was not as great as was obtained in Example 1.

Example 13 A dyeing was made at a temperature of about 250 F.(approximately 50 pounds pressure) on 2.5 parts of bleached,unmercerized cotton in the apparatus described in U. S. P. 2,405,167using a dye bath containing 0109- part ofreal dye having Color Index No.1098, one partof sodium chlorate,

A goodstrong, bright reddish-orange shadewas obtained. I A. controldyeing in which, no sodiumchlorate was present, but. otherwise made as,above, had a dull yellow shade.

. Example 14 '500 parts ofNojZOs, Z-ply, natural cotton yarn in packageform were wet'out' with 7000 parts of a solution of a surface-activeanionic-ma terial which had been preheated to 190 F. This was then dyedin a dye bath containing nine parts of real dye having Color Index No.1098,15 parts of a surface-active anionic material and: 22.5- parts ofsodium chlorate in a liter of water, mak-' ing adye bath volume 0f8000parts.

The dye dispersion was-first heated to 190 F; and then circulatedthrough the wet-out package for ten minutes, after which 200 parts of:30 B: sodium hydroxide which had-been preheated. to 190 F. were added tothe dye bath and circulated for five minutes, after which parts of solidsodium hydrosulfite were. added and circulated for 25 minutes. The spentdye bath was then flushed with water from the machine, the dye wasoxidized with 2% of 100-volume. hydrogen,

the dyebath. The package-dyed in the control bath was 'dull andyellower.

Example 15 900 parts of the real dye, having Color Index No. 1098, wereground and dry-blended with 250 parts of potassium chlorate. Ten partsof'cotton were dyed in. a bath containing, 0.115 part of this blend, 3parts of sodiumthydroxide, and 3 parts-of sodium hydrosulfitein'400'partsofwater using the general method of-E'xamp'le 1.Theresultant dyeing was stronger, redder and brighter than a controldyeing made from a bath containing the same amount of real dye, alkaliand hydrosulfite but omitting the potassium chlorate.

Example 16 Example 17 960 parts of the dye having Color Index No.

1096 and 2,400 parts of sodium bromate were ground and dry blended togive a homogeneous mixture. Ten parts of rayon yarn were dyed in a bathcontaining 0.35 part of this blend, 3 parts of sodium hydroxide, and 3parts of sodium hy- Ten parts of cotton drosulfite in 400 parts of waterby the general method used in Example 1. The yarn dyed in the bathcontaining the sodium bromate was redder and brighter than the controldyeing.

Example 18 Example 19 462.5 parts of the 20% wet press cake containingabout 92.5 parts of the dye having Color Index No. 1098 and 400 parts ofsodium chlorate were stirred together and then made up to 1,000 partswith water. One part of this paste was substituted for the one part ofthe paste of the preceding example, the dyeings were made as in thepreceding example, and the results were satisfactory.

Example 20 The procedure of the preceding example was repeated exceptpart of the water needed to bring the paste to 1,000 parts was replacedwith glycerine to give a glycerine content of %10% on the final weight.Dyeings made with pastes containing glycerine were quite satisfactory.

Example 21 The procedure of the preceding example was repeated exceptthe glycerine was replaced by ethylene glycol. Cotton yarn dyed withthis paste is commercially satisfactory.

Example 22 The procedure of the preceding example was repeated exceptthe wet press cake was dispersed with parts of the sodium salt ofdi-sulfo-dinaphthyl methane, the humectant then added and the paste madeup to 1,000 parts. Cotton yarn dyed in a bath containing one part ofthis 8 paste but otherwise dyed as in Example 19 gave satisfactoryresults.

I claim:

1. A method of vat dyeing fibrous material to which alkali metal saltsof the leuco vat pyranthrone dye are substantive with a pyranthrone dye,which comprises dyeing the material at high temperature approaching theboiling point of water in a bath containing the dyestuif, strong alkali,reducing agent, and an amount of an inorganic halogenate at leastonequarter the weight of the real dyestufi.

2. A method according to claim 1 in which the halogenate is sodiumchlorate.

3. A method according to claim 2 in which the dyestuif is pyranthrone.

4. A method according to claim 2 in which the dyestufi isdibromopyranthrone.

5. A method according to claim 1 in which the dyestuif is pyranthrone.

6. A method acording to claim 1 in which the dyestufi isdibromopyranthrone.

7. As a new article of manufacture a blend of a pyranthrone vat dyestuffwith an amount of an inorganic halogenate at least one-quarter theweight of the real dyestuff.

8. An article of manufacture according to claim '7 in which thehalogenate is sodium chlorate.

9. An article of manufacture according to claim 8 in which the dyestufiis pyranthrone.

10. An article of manufacture according to claim 8 in which the dyestuffis dibromopyranthrone.

11. An article of manufacture according to claim 7 in which the dyestuifis pyranthrone.

12. An article of manufacture according to claim 7 in which the dyestufiis dibromopyranthrone.

JERRY M. MECCO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,029,999 Grieshaber Feb. 4, 19392,146,646 Nusslein Feb. '7, 1939 2,383,393 Kienle Aug. 21, 1945

1. A METHOD OF VAT DYEING FIBROUS MATERIAL TO WHICH ALKALI METAL SALTSOF THE LEUCO VAT PYRANTHRONE DYE ARE SUBSTANTIVE WITH A PYRANTHRONE DYE,WHICH COMPRISES DYEING THE MATERIAL AT HIGH TEMPERATUE APPROACHING THEBOILING POINT OF WATER IN A BATH CONTAINING THE DYESTUFF, STRONG ALKALI,REDUCING AGENT, AND AN AMOUNT OF INORGANIC HALOGENATE AT LEAST ONEQUATERTHE WEIGHT OF THE REAL DYESTUFF.